Sealed multi-pane sealed window units have become standards for new and renovation construction within industrialized nations. Architectural detail is provided by the fixing of false muntin bars between panes of glass within such units. Such detail frequently requires multiple false muntin bars to intersect to form distinct patterns within the unit. The positioning of muntin bars commonly results in muntin bar ends intersecting with the perimeter of a window unit in other than an orthogonal relationship between the muntin bar and the unit perimeter forming, for example, a sunburst or radiating pattern. The securing of muntin bars in place during and following manufacture is critical in that any shifting from proper alignment will result in an unacceptable appearance. The method of or apparatus securing muntin bars, at the perimeter of such units, must not interfere with the sealing method of the unit. A method of fixing the position of muntin bars at a window unit perimeter has included the fixing of a pin at the muntin bar end with the pin to be received into a hole prepared in the window unit perimeter at the frame. The pin and hole combination required additional manufacturing steps and, in the case of sealed units, created potential sealant breaches.
The advent of new manufacturing techniques and the production of foam strip sealed and butyl sealed inert gas filled window units renders problematic or unusable methods of apparatus, for the positioning of muntin bars, disclosed in the prior art. Maintenance of gas integrity within such units is of paramount importance in insuring continued heat exchange properties and eliminating the potential for formation of condensation within the interior of the unit. Existing prior art is unlikely to provide for the maintenance of such characteristics with a substantial likelihood that the interior of sealed units will experience a breach of the seal. The apparatus disclosed herein is principally adapted for use with foam strip, butyl and other similar pliable or flexible seal systems.
Prior art which is distinguished includes the following which, along with additional patents, are disclosed in an information disclosure statement. U.S. Pat. No. 3,686,814 to Anderson discloses a barbed clip for use with wood frames and a clip suitable for locking behind a bead on a metal window frame. U.S. Pat. No. 4,644,721 to Bloomquist et al. relates to a clip for securing a muntin bar in a single pane window for ease of removal of the muntin bar for cleaning purposes. U.S. Pat. No. 4,890,435 to Wilkening et al. demonstrates a method of mounting muntin bars on the exterior of a multi-pane unit. U.S. Pat. No. 4,060,950 to Rackard et al. discloses a clip for the interconnection of muntin bars at their point of crossing. U.S. Pat. No. 5,574,651 to McKeegan et al. discloses a keeper at the end of a muntin bar having a protrusion secured within an aperture within the frame. U.S. Pat. No. 3,108,336 to Tate demonstrates an end clip limited to an orthogonal orientation. U.S. Pat. No. 5,154,034 to Stanek shows an edge clip with a pad form element in contact with the seal material causing a pressure point break of the seal integrity with the window perimeter. U.S. Pat. No. 3,791,095 to Martin illustrates edge clips with a semi-circular edge sized to fit within one-sixteenth inch bores in the spacing strips. U.S. Pat. No. 5,678,376 to Poma demonstrates edge clips with protrusions received into apertures in the frame. U.S. Pat. No. 5,325,579 to Baier shows a multi-pane structure with a muntin bar grid. U.S. Pat. No. 4,437,284 to Cribben et al. shows muntin bars fixed with pins at the frame. U.S. Pat. No. 3,307,316 to Gray shows a pin fixing method at the frame. U.S. Pat. No. 4,989,384 to Kinghorn et al. illustrates a locating pin received in an opening in the perimeter bar. U.S. Pat. No. 3,645,058 to Jacobson discloses muntin bars with cam or wedge locking with a window sash. U.S. Pat. No. 3,340,661 to Krieger illustrates an edge clip composed of a tongue member received into a slot and a toothed member engaging a wood sash frame member. U.S. Pat. No. 4,949,521 to Riegelman et al. disclosed external muntin bars affixed with screw means. U.S. Pat. No. 4,970,840 to Ouellette et al. discloses a muntin end piece bearing a stud which snap fits into a hollow of the sash. U.S. Pat. No. 3,099,865 to Burnett demonstrates a magnetic pin means of securing muntin bars in place. U.S. Pat. No. 5,363,625 to Philippi shows a structural framework having end portions fixed in place by posts received into sockets. U.S. Pat. Nos. 5,313,761 and 5,678,377 to Leopold shows an edge clip having fingers received into a hollow muntin bar and secured a sash by laches received through apertures in the sash. U.S. Pat. No. 5,048,252 to Osborn illustrates muntin bars fixed with cam locks. U.S. Pat. No. 3,293,817 to MacGregor shows muntin bars fixed by a stud, at the sash, received into a slot in the muntin bar. The patents referred to herein are provided herewith in an Information Disclosure Statement in accordance with 37 CFR 1.97.